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wireshark/epan/dissectors/packet-flip.c
Michael Mann 1e60d63c8c Create call_data_dissector() to call data dissector. 
This saves many dissectors the need to find the data dissector and store a handle to it.

There were also some that were finding it, but not using it.
For others this was the only reason for their handoff function, so it could be eliminated.

Change-Id: I5d3f951ee1daa3d30c060d21bd12bbc881a8027b
Reviewed-on: https://code.wireshark.org/review/14530
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-03-20 17:38:03 +00:00

507 lines
16 KiB
C
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/* packet-flip.c
* Routines for FLIP packet dissection
*
* Copyright 2009, Juha Siltanen <juha.siltanen@nsn.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/*
* FLIP (Flow Layer Internal Protocol) is a proprietary protocol
* developed by Nokia Solutions and Networks (previous was 'Nokia Siemens Networks').
*/
/*
* Version information
*
* Version 0.0.1, November 23rd, 2009.
*
* Support for the basic and checksum headers.
*
* Version 0.0.2, August 26th, 2010.
*
* Support for payload dissecting.
*
* Version 0.0.3, September 14th, 2010.
*
* Bugfix: sorting by protocol didn't always fill in the protocol column.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/etypes.h>
#include <epan/decode_as.h>
#include <epan/in_cksum.h>
#include <epan/prefs.h>
#include <epan/rtp_pt.h>
void proto_register_flip(void);
void proto_reg_handoff_flip(void);
static int proto_flip = -1;
/* BASIC */
static int hf_flip_basic_e = -1;
static int hf_flip_basic_reserved = -1;
static int hf_flip_basic_flowid = -1;
static int hf_flip_basic_seqnum = -1;
static int hf_flip_basic_len = -1;
/* CHECKSUM */
static int hf_flip_chksum_etype = -1;
static int hf_flip_chksum_spare = -1;
static int hf_flip_chksum_e = -1;
static int hf_flip_chksum_chksum = -1;
#define FLIP_BASIC (0)
#define FLIP_CHKSUM (1)
#define FLIP_BASIC_HDR_LEN (8)
#define FLIP_CHKSUM_HDR_LEN (4)
#define FLIP_EXTENSION_HDR_MIN_LEN (4)
static const value_string flip_etype[] = {
{ FLIP_CHKSUM, "Checksum" },
{ 0, NULL }
};
static dissector_table_t subdissector_table;
static gint ett_flip = -1;
static gint ett_flip_basic = -1;
static gint ett_flip_chksum = -1;
static gint ett_flip_payload = -1;
static void flip_prompt(packet_info *pinfo _U_, gchar* result)
{
g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Decode FLIP payload protocol as");
}
static gpointer flip_value(packet_info *pinfo _U_)
{
return 0;
}
/* Dissect the checksum extension header. */
static int
dissect_flip_chksum_hdr(tvbuff_t *tvb,
packet_info *pinfo,
proto_tree *tree,
guint16 computed_chksum,
gboolean *ext_hdr_follows_ptr)
{
proto_tree *chksum_hdr_tree;
guint32 dw;
guint8 chksum_hdr_etype;
guint8 chksum_hdr_ext;
guint16 chksum_hdr_chksum;
gint bytes_dissected;
gint offset;
chksum_hdr_tree = NULL;
bytes_dissected = 0;
offset = 0;
dw = tvb_get_ntohl(tvb, offset);
chksum_hdr_etype = (guint8) ((dw & 0xFF000000) >> 24);
chksum_hdr_ext = (guint8) ((dw & 0x00010000) >> 16);
chksum_hdr_chksum = (guint16) (dw & 0x0000FFFF);
/* The actually shouldn't be any headers after checksum. */
if (chksum_hdr_ext == 1) {
*ext_hdr_follows_ptr = TRUE;
}
else {
*ext_hdr_follows_ptr = FALSE;
}
if (tree) {
chksum_hdr_tree = proto_tree_add_subtree(tree, tvb, offset + 0, 4,
ett_flip_chksum, NULL, "Checksum Header");
/* ETYPE: 8 bits */
proto_tree_add_uint_format_value(chksum_hdr_tree, hf_flip_chksum_etype,
tvb, offset + 0, 1, dw,
"%s", val_to_str_const(chksum_hdr_etype,
flip_etype,
"Unknown"));
/* SPARE: 7 bits */
proto_tree_add_item(chksum_hdr_tree, hf_flip_chksum_spare, tvb, offset, 4, ENC_BIG_ENDIAN);
/* EXT HDR: 1 bit */
proto_tree_add_item(chksum_hdr_tree, hf_flip_chksum_e,
tvb, offset, 4, ENC_BIG_ENDIAN);
/* CHKSUM: 16 bits. */
proto_tree_add_uint_format_value(
chksum_hdr_tree,
hf_flip_chksum_chksum,
tvb, offset + 2, 2,
chksum_hdr_chksum,
"0x%04x [%s] (computed 0x%04x)",
chksum_hdr_chksum,
((chksum_hdr_chksum == computed_chksum) ? "Correct" : "Incorrect"),
computed_chksum);
}
/* Show faulty checksums. */
if (computed_chksum != chksum_hdr_chksum) {
col_add_fstr(pinfo->cinfo, COL_INFO,
"Checksum 0x%04x [%s] (computed 0x%04x)",
chksum_hdr_chksum,
((chksum_hdr_chksum == computed_chksum) ?
"Correct" : "Incorrect"),
computed_chksum);
}
bytes_dissected += FLIP_CHKSUM_HDR_LEN;
return bytes_dissected;
} /* dissect_flip_chksum_hdr() */
/* Protocol dissection */
static int
dissect_flip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
proto_item *ti = NULL;
proto_tree *flip_tree = NULL;
proto_tree *basic_hdr_tree = NULL;
tvbuff_t *flip_tvb;
guint32 dw1;
/* Basic header fields. */
guint8 basic_hdr_ext;
guint32 basic_hdr_flow_id;
guint16 basic_hdr_len;
gboolean ext_hdr = FALSE;
gint bytes_dissected = 0;
gint payload_len;
gint frame_len;
gint flip_len;
gint offset = 0;
/* Error handling for basic header. */
gboolean is_faulty_frame = FALSE;
/* Show this protocol as FLIP. */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "FLIP");
/*
* The frame can be faulty in several ways:
* - too short (even for the basic header)
* - length inconsistent (header and frame info different)
* - checksum doesn't check out
* - extension header is indicated, but the frame is too short for it
* - unknown extension header type
*/
/* Check that there's enough data at least for the basic header. */
frame_len = tvb_captured_length(tvb);
if (frame_len < FLIP_BASIC_HDR_LEN) {
return 0;
}
bytes_dissected += FLIP_BASIC_HDR_LEN;
/* Process the first 32 bits of the basic header. */
dw1 = tvb_get_ntohl(tvb, offset + 0);
basic_hdr_ext = ((dw1 & 0x80000000) >> 31);
basic_hdr_flow_id = (dw1 & 0x0FFFFFFF);
/* Process the second 32 bits of the basic header. */
basic_hdr_len = (guint16) (tvb_get_ntohl(tvb, offset + 4) & 0x0000FFFF);
/* Does the basic header indicate that an extension is next? */
if (basic_hdr_ext == 1) {
ext_hdr = TRUE;
}
flip_len = basic_hdr_len;
/*
* Check the length value.
*/
if ((flip_len < FLIP_BASIC_HDR_LEN) || (flip_len > frame_len)) {
/* Faulty frame. Show the basic header anyway for debugging. */
is_faulty_frame = TRUE;
}
/* Fill in the info column. */
col_add_fstr(pinfo->cinfo, COL_INFO,
"FlowID %s", val_to_str(basic_hdr_flow_id, NULL, "0x%08x"));
flip_tvb = tvb_new_subset_length(tvb, 0, frame_len);
/* We are asked for details. */
if (tree) {
ti = proto_tree_add_protocol_format(
tree, proto_flip, flip_tvb, 0, flip_len,
"NSN FLIP, FlowID %s",
val_to_str(basic_hdr_flow_id, NULL, "0x%08x"));
flip_tree = proto_item_add_subtree(ti, ett_flip);
/* basic header */
basic_hdr_tree = proto_tree_add_subtree(flip_tree, flip_tvb, offset, 8, ett_flip_basic, NULL, "Basic Header");
/* Extension header follows? 1 bit. */
proto_tree_add_item(basic_hdr_tree, hf_flip_basic_e, flip_tvb, offset, 4, ENC_BIG_ENDIAN);
/* Reserved: 3 bits. */
proto_tree_add_item(basic_hdr_tree, hf_flip_basic_reserved, flip_tvb, offset, 4, ENC_BIG_ENDIAN);
/* Flow ID: 28 bits. */
proto_tree_add_item(basic_hdr_tree, hf_flip_basic_flowid, flip_tvb, offset, 4, ENC_BIG_ENDIAN);
/* Sequence number: 16 bits. */
proto_tree_add_item(basic_hdr_tree, hf_flip_basic_seqnum, flip_tvb, offset + 4, 2, ENC_BIG_ENDIAN);
/* Packet length: 16 bits. */
proto_tree_add_item(basic_hdr_tree, hf_flip_basic_len, flip_tvb, offset + 6, 2, ENC_BIG_ENDIAN);
}
offset += FLIP_BASIC_HDR_LEN;
/*
* Process faults found when parsing the basic header.
*/
if (is_faulty_frame == TRUE) {
if (flip_len > frame_len) {
col_add_fstr(pinfo->cinfo, COL_INFO,
"Length mismatch: frame %d bytes, hdr %d bytes",
frame_len, flip_len);
}
else if (flip_len < FLIP_BASIC_HDR_LEN) {
col_add_fstr(pinfo->cinfo, COL_INFO,
"Invalid length in basic header: %d bytes", flip_len);
}
goto DISSECT_FLIP_EXIT;
}
/*
* Now we know that the basic header is sensible.
*/
payload_len = basic_hdr_len - FLIP_BASIC_HDR_LEN;
/*
* Dissect extension headers (if any).
*/
if ((ext_hdr == TRUE) && (payload_len < FLIP_EXTENSION_HDR_MIN_LEN)) {
col_add_fstr(pinfo->cinfo, COL_INFO,
"Extension header indicated, but not enough data");
goto DISSECT_FLIP_EXIT;
}
while ((ext_hdr == TRUE) && (payload_len >= FLIP_EXTENSION_HDR_MIN_LEN)) {
/* Detect the next header type. */
guint8 ext_hdr_type;
gint bytes_handled;
guint16 computed_chksum;
tvbuff_t *chksum_tvb;
ext_hdr_type = tvb_get_guint8(flip_tvb, offset);
switch (ext_hdr_type) {
case FLIP_CHKSUM:
/* Calculate checksum, let the chksum dissector verify it. */
{
vec_t vec[2];
SET_CKSUM_VEC_TVB(vec[0], flip_tvb, 0, bytes_dissected + 2);
SET_CKSUM_VEC_TVB(vec[1], flip_tvb, bytes_dissected + 4,
flip_len - (bytes_dissected + 4));
computed_chksum = in_cksum(&vec[0], 2);
/* Checksums handled in network order. */
computed_chksum = g_htons(computed_chksum);
}
chksum_tvb = tvb_new_subset_length(flip_tvb, offset,
FLIP_CHKSUM_HDR_LEN);
/* Note that flip_tree is NULL if no details are requested. */
bytes_handled = dissect_flip_chksum_hdr(chksum_tvb,
pinfo,
flip_tree,
computed_chksum,
&ext_hdr);
bytes_dissected += bytes_handled;
payload_len -= bytes_handled;
offset += bytes_handled;
break;
default:
/* Unknown header type. */
col_add_fstr(pinfo->cinfo, COL_INFO,
"Invalid extension header type 0x%02x", ext_hdr_type);
goto DISSECT_FLIP_EXIT;
break;
}
}
/*
* Show payload (if any) as bytes.
*/
if (payload_len > 0) {
tvbuff_t *payload_tvb;
gint data_len;
payload_tvb = tvb_new_subset_length(flip_tvb, offset, payload_len);
/* Functionality for choosing subdissector is controlled through Decode As as FLIP doesn't
have a unique identifier to determine subdissector */
data_len = dissector_try_uint(subdissector_table, 0, payload_tvb, pinfo, tree);
if (data_len <= 0)
{
data_len = call_data_dissector(payload_tvb, pinfo, tree);
}
bytes_dissected += data_len;
} /* if (payload_len > 0) */
DISSECT_FLIP_EXIT:
return bytes_dissected;
} /* dissect_flip() */
/* Protocol initialization */
void
proto_register_flip(void)
{
static hf_register_info hf[] = {
/*
* Basic header.
*/
{&hf_flip_basic_e,
{"Extension Header Follows", "flip.basic.e", FT_BOOLEAN, 32,
TFS(&tfs_yes_no), 0x80000000, NULL, HFILL}
},
{&hf_flip_basic_reserved,
{"Reserved", "flip.basic.reserved", FT_UINT32, BASE_DEC,
NULL, 0x70000000, "Basic Header Reserved", HFILL}
},
{&hf_flip_basic_flowid,
{"FlowID", "flip.basic.flowid", FT_UINT32, BASE_HEX,
NULL, 0x0FFFFFFF, "Basic Header Flow ID", HFILL}
},
{&hf_flip_basic_seqnum,
{"Seqnum", "flip.basic.seqnum", FT_UINT16, BASE_DEC_HEX,
NULL, 0x0, "Basic Header Sequence Number", HFILL}
},
{&hf_flip_basic_len,
{"Len", "flip.basic.len", FT_UINT16, BASE_DEC_HEX,
NULL, 0x0, "Basic Header Packet Length", HFILL}
},
/*
* Checksum header.
*/
{&hf_flip_chksum_etype,
{"Extension Type", "flip.chksum.etype", FT_UINT32, BASE_DEC,
VALS(flip_etype), 0xFF000000, "Checksum Header Extension Type", HFILL}
},
{&hf_flip_chksum_spare,
{"Spare", "flip.chksum.spare", FT_UINT32, BASE_DEC_HEX,
NULL, 0x00FE0000, "Checksum Header Spare", HFILL}
},
{&hf_flip_chksum_e,
{"Extension Header Follows", "flip.chksum.e", FT_BOOLEAN, 32,
TFS(&tfs_yes_no), 0x00010000, NULL, HFILL}
},
{&hf_flip_chksum_chksum,
{"Checksum", "flip.chksum.chksum", FT_UINT32, BASE_HEX,
NULL, 0x0000FFFF, NULL, HFILL}
}
};
static gint *ett[] = {
&ett_flip,
&ett_flip_basic,
&ett_flip_chksum,
&ett_flip_payload
};
module_t *flip_module;
/* Decode As handling */
static build_valid_func flip_da_build_value[1] = {flip_value};
static decode_as_value_t flip_da_values = {flip_prompt, 1, flip_da_build_value};
static decode_as_t flip_da = {"flip", "FLIP Payload", "flip.payload", 1, 0, &flip_da_values, NULL, NULL,
decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL};
proto_flip = proto_register_protocol(
"NSN FLIP", /* name */
"FLIP", /* short name */
"flip" /* abbrev */
);
proto_register_field_array(proto_flip, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
subdissector_table = register_dissector_table("flip.payload", "FLIP subdissector", proto_flip, FT_UINT32, BASE_HEX, DISSECTOR_TABLE_NOT_ALLOW_DUPLICATE);
flip_module = prefs_register_protocol(proto_flip, NULL);
/* Register preferences - now obsolete because of Decode As*/
prefs_register_obsolete_preference(flip_module, "decoding_mode");
prefs_register_obsolete_preference(flip_module, "heur_enabled_protocols");
prefs_register_obsolete_preference(flip_module, "heur_decode_rtp");
prefs_register_obsolete_preference(flip_module, "heur_decode_rtcp");
prefs_register_obsolete_preference(flip_module, "forced_protocol");
prefs_register_obsolete_preference(flip_module, "forced_decode");
register_decode_as(&flip_da);
} /* proto_register_flip() */
/* Protocol handoff */
void
proto_reg_handoff_flip(void)
{
dissector_handle_t flip_handle;
flip_handle = create_dissector_handle(dissect_flip, proto_flip);
dissector_add_uint("ethertype", ETHERTYPE_FLIP, flip_handle);
} /* proto_reg_handoff_flip() */
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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